1. Field of the Invention
This invention relates to a process for the production of mevalonic acid. In particular, it relates to a process for economically producing mevalonic acid at a high yield.
It is known that mevalonic acid exists in the form of an acid and in the form of a lactone which may be readily converted into each other. Unless otherwise noted, the term "mevalonic acid" as used herein involves both of these forms.
2. Description of the Prior Art
Mevalonic acid, which was isolated by Wright et al. for the first time [cf. Journal of the American Chemical Society, 78, 5273-5275 (1956)], is known as an important intermediate in the synthesis of various isoprenoids such as cholesterol.
Further, mevalonic acid takes an important role in the metabolism in organisms. For example, it promotes the growth of various microorganisms, animals and/or plants. Therefore it is employed as a growth promoter for microorganisms, animals and plants. Furthermore, mevalonic acid is employed as a precursor for, e.g., pyrethroid agricultural chemicals, ubiquinone, dolichol and fat-soluble vitamins.
It is preferable to use natural (R-form) mevalonic acid for these purposes. However natural mevalonic acid is hardly available. Thus synthetic racemic mevalonic acid has been used hitherto.
A known process for the production of natural mevalonic acid comprises using a microorganism such as Saccharomycopsis fibuligera and thus accumulating mevalonic acid in a medium at a yield of 12 mg/ml at the highest (cf. Japanese Patent Laid-Open No. 216484/1988, No. 216485/1988, No. 216486/1988 and No. 216487/1988). However it has been demanded to establish a process whereby mevalonic acid can be more efficiently accumulated at a higher yield.
It is also demanded to develop a process therefor wherein inexpensive culture materials are used, since these known methods require expensive materials such as malt extract and meat extract.